Steam for Linux

i tried to install steam on ubuntu 10.04 via the steam_latest.deb package. but something went wrong. first the install process failed. the installer was unresponsiove for minuts, then asked me to let it set up a database on my system, then was unresponsive again, then finished. but no steam client was installed after that. i tried again. it says now, a newer version is already installed. i used synaptic package manager to see what is installed. but nothing steam realeted is shown as installed on the system.i also saw, that there is a package "steam-launcher" available. so i tried to install this, but it says it has unresolvable dependencies. ....

what is so hellish wrong with my system, that nothing is working here?